Replacing the Mass Air Flow (MAF) sensor on 2001 and later models [Toyota RAV4 XA10]

The air flow meter sensor is located on the air intake pipe. Air flow enters the engine through a heated wire element meter that forms part of a bridge circuit. The current passing through this wire element maintains its constant temperature at a constant level, which is higher than the temperature of the air entering the engine. The mass of air is determined by the current strength. The voltage signal is processed in the engine control unit in parallel with the crankshaft speed parameter. The temperature sensor is installed in the air flow meter so that the output signal is independent of the temperature of the air entering the engine. Based on the information from the sensor, the engine control unit calculates the pulse width supplied to the injectors, which results in a change in the amount of fuel supplied to the engine cylinders.

To replace the mass air flow (MAF) sensor on 2001 and later models, proceed as follows:

• turn off the ignition and disconnect the ground wire from the battery;
• disconnect the electrical connector from the sensor;
• remove the air filter housing;

• remove the 2 screws and the air flow meter sensor with the sealing rings (figure 7.9).

Installation is carried out in the reverse order of removal. When installing the sensor, use new O-rings.

[The original text is posted on toyotaman.ru]